1. Field of the Invention
The present invention relates to a focus control apparatus. More particularly, it relates to a focus control apparatus which allows an area desired to be brought into focus to be specified within a range of a camera image being picked up by a television camera and auto-focuses on a subject in the area.
2. Related Art
The present applicant has proposed, in Japanese Patent Application Laid Open No. 2004-117492, a television camera system which allows an AF area desired to be brought into focus to be specified in a viewfinder screen within a range of a camera image being picked up by a broadcast camera and auto-focuses on a subject in the AF area.
In the television camera system, a joystick and the like used to superimpose an AF frame on the viewfinder screen and move the AF frame to a specified position of the AF area is cited as an AF area specifying device for use to specify an AF area in the viewfinder screen. When a cameraperson presses a switch after specifying an AF area with the joystick, the autofocus function comes into action to focus on the subject in the AF area automatically.
Incidentally, as described in Japanese Patent Application Laid Open No. 2003-279832, broadcast cameras are usually used being mounted on a pan head attached to a pedestal dolly or tripod. The cameraperson points the broadcast camera in a desired direction through pan and tilt operations by gripping two panrods, adjusts focal length by manually operating a zoom demand mounted on one of the two panrods, and adjusts focus by manually operating a focus controller mounted on the other panrod.
In the case of a broadcast camera equipped with the joystick and focus controller for use to specify an AF area, the cameraperson first specifies an AF area with the joystick, brings the AF area into approximate focus by manually operating the focus controller, and then automatically brings the AF area into perfect focus by operating the switch.